Biochemistry › Globular and Fibrous Proteins
Which proteins are generally water-soluble?
Globular proteins
Fibrous proteins
Both globular fibrous proteins
Neither globular nor fibrous proteins
In a globular protein, the amino acid chain can twist in a way that polar groups lie at the protein's surface. This allows the protein to interact with water and enhances the protein's solubility in water. This does not occur in fibrous proteins, so fibrous proteins are insoluble in water.
An O-linked glycoprotein has a sugar attached to an oxygen atom on what amino acid(s)?
Serine or threonine
Serine only
Methionine only
Methionine or threonine
Threonine only
An O-linked glycoprotein is a protein that has a sugar attached to it. It is called O-linked because the sugar is attached to an oxygen atom on either a threonine residue or a serine residue within the protein.
Which of the following is false about actin filaments?
They require GTP for assembly
They are made up of G-actin
Nucleotide hydrolysis promotes dissociation of actin filaments
2 microfilaments combine to make a coiled filament
Growth of the actin chain occurs at the plus (+) end
Actin chain growth occurs at the (+) end of the chain, and nucleotide hydrolysis promotes dissociation of actin chains. 2 microfilaments of G-actin monomers make 1 filament of F-actin. However, actin filament assembly is powered by ATP, not GTP.